Security methods based on memory data encoded into magnetic cards such as personal identification numbers or passwords are widely used in today's business, industrial, and governmental communities. With the increase in electronic transactions and verification there has also been an increase in lost or stolen cards, and forgotten, shared, or observed identification numbers or passwords. Because the magnetic cards offer little security against fraud or theft there has been a movement towards developing more secure methods of automated recognition based on unique, externally detectable, personal physical anatomic characteristics such as fingerprints and retina prints, or external behavior characteristics; for example, writing style and voice patterns. Known as biometrics, such techniques are effective in increasing the reliability of recognition systems by identifying a person by characteristics that are unique to that individual. Some representative techniques include fingerprint recognition focusing on external personal skin patterns, hand geometry concentrating on personal hand shape and dimensions, retina scanning defining a person's unique blood vessel arrangement in the retina of the eye, voice verification distinguishing an individual's distinct sound waves, and signature verification.
Biometric recognition can be used in “identification mode”, where the biometric system identifies a person from the entire enrolled population by searching a database for a match. A system can also be used in “verification mode”, where the biometric system authenticates a person's claimed identity from his/her previously enrolled pattern of identification data. In many biometric applications there is little margin for any inaccuracy in either the identification mode or the verification mode. These applications may include physical access to restricted areas; and access to computer systems containing sensitive information used by the military services, intelligence agencies, and other security-critical Federal organizations. Also, there are law enforcement applications which include home incarceration, parole programs, and physical access into jails or prisons. Finally, government sponsored entitlement programs that rely on the Automated Fingerprint Identification System (AFIS) for access are important to deter fraud in social service programs by reducing duplicate benefits or even continued benefits after a recipient's demise.
With the advancement of lasers and synthetic polymers there is currently available technology to reproduce a human body part with the requisite unique physical patterns and traits of a particular individual. In high level security systems, where presentation of a unique skin or body pattern needs to be verified for entry, a counterfeit model could be produced, thereby allowing unauthorized entry into a secured facility by an imposter. As these capabilities evolve and expand, thereby providing more realistic body parts with unique skin patterns or specific geometries, there is a greater need to verify whether the body part offered for identification purposes is a counterfeit reproduction or even a body part of a deceased authorized individual.
Current commercially available biometric methods and systems use only externally visible distinguishing characteristics for identification; for example, fingerprints, hand geometry and blood vessel patterns. To date, the most widely used method is fingerprinting but there are several problems which have been encountered including false negative identifications due to dirt, moisture and grease on the print being scanned. Additionally, some individuals have insufficient detail of the ridge pattern on their print due to trauma or a wearing down of the ridge structure. To overcome these problems, biometric methods have been introduced using ultrasonic technology to scan the subsurface features of the fingerprint ridge pattern which contain all of the features that the surface skin displays. However, this method does not provide a fail proof system because a fingerprint, both the surface and subsurface ridge pattern, can be easily reproduced with today's modern technology.
To increase security, attempts have been made to use internal implants which comprise a coded computer chip to identify a person or animal. Some of these internal implants have been used in tagging animals, especially if the animals are highly valued; for example, a prize bull, expensive breeding stock, race horses and even family pets. But, even these implants are not without risk. These implants may be helpful in identifying an animal but only if the implants have not been removed. Once removed there is no discernible information to identify a lost or stolen animal. Furthermore, if internal implants are used for access into a secure facility it would be relatively easy to remove the implanted chip from an authorized individual, and subsequently implant the chip into an unauthorized individual.
Accordingly, there is a need for more economic and reliable automated biometric recognition methods and systems which verify the identity of an individual or animal using unique characteristics that are not readily removed or replicated. This would eliminate concerns regarding the removal of an internal implant, fingerprints that are unidentifiable due to dirt, grease, moisture or external surface deterioration, and the possibility of deceiving a system with an artificial reproduction of a unique distinguishing characteristic used for identification.